Telephone system



Jan. 13, 1942. M; LANGIER y 2,270,129

TEL/PHONE SYSTEM Filed May 27, 1939 2 sheets-sheet 1 .Fly-1.

' ATTO/PN X Jan. .13, 1942.

M. LANGER TELEPHONE SYSTEM 'Filed May 27, 19:59

..2 Sheets-Sheet 2 Patented Jan. 13, 1942 TELEPHONE SYSTEM Max Langer, Berlin-Hermsdorf, Germany, as-

signor to Fides Gesellschaft fr die Verwaltung und Verwertung von gewerblichen Schutzrechten mit beschrnkter Haftung, Berlin, Germany, a corporation of Germany Application May 27, 1939, Serial No.7276,141

' In Germany May 30, 1938 20 Claims.

The present invention is concerned with a circuit arrangement for determining calling subscribers stations in remote signalling installations, in particular automatic telephone installations of the type in which an impulse sending arrangement associated in common with a group of subscribers stations transmits impulse trains to a registering arrangement to record a calling subscribers number.

The object of the present invention is to introduce simplication and improvement of the arrangements necessary for marking the calling subscribers numbers and in particular to provide a simplified arrangement for making use of the subscribers meter for this purpose. The result is obtained by providing the subscribers meter with one contact for marking each call number these contacts being so arranged that they form points of a co-ordinate system and on the operation of a subscribers meter which initiates the determination of a call number the closing of one of the marking circuits extending over both co-ordinate arrangementsis brought about by means of the corresponding meter, in which circuit the number of the calling subscriber is made effective on switch means marking a common impulse sender.

The drawings comprising Figs. 1 and 2 together form a circuit diagram showing the line identifying arrangement and impulse sender. For the sake oi simplicity all unnecessary equipment has been omitted from the drawings. The two iigures should be placed side by side with Fig. 1 to the left of Fig. 2.

At the top of Figs. 1 and 2 is illustrated the part of a connecting path which extends from a subscriber T11l over the indicating preselector VW, the first group selector IGW, and a repeater UE from which a two-conductor junction line extends for example to a distant exchange. As is indicated by the dotted lines outgoing from the first group selector IGW, the connection may pass through any number of `additional selector switches for reaching repeater UE. The repeater transfers the impulse train sent out from In addition to the calling i iii) subscribers number other records can be made by the registering arrangement (called number, duration of connection, amount of fee, period, date, etc). 1

Below the connecting path, and separated from it in the diagram by the horizontal dot and dash line isa contact field and control relay arrangement KR and an impulse sender SS; the two are separated from one another in Fig. 2 by a Vertical dot-and-dash line KR lying to the left of this line and SS to the right. The arrangement KR consists of a number of control relays and contacts of the meters associated with the individual subscribers. The meter contacts are fastened together, corresponding to the call number of the individual subscribers, in groups of 100. In Fig. 1 the contact eld IH (first hundred) is shown in its entirety, while the contact fields 2H (second hundred) and 3H (third hundred), are only partially shown.

The impulse sender SS after the marking of the number by means of the control relays transmits the impulse trains corresponding to the individual digits of the calling subscribers number over the junction line to the printing arrangement.

In connection with the drawings detailed description will be given only for the circuits and the seizing relay C of the group selector and the cut-01T relay T of the pre-selector are energised. The meter Za cannot atl present operate. When the first and second group `selectors are set, a blocking circuit is completed in which the test relay P of the iirst group selector and the seizing relay CI in the repeater are energized.

The arrangement shown in Figs. 1 and 2 makes possible the determination and transmission of the calling subscribers number at any desired instant. It can, for example, be accomplished during the setting up of a connection, after the reply of the called station or after the connection has been terminated. It is assumed here that the reply of thecalled subscriber is the signal for initiating the determination and transmitting of the calling subscribers number.

It is a common practice to connect potential to one conductor of the talking circuit when the calling subscribers meter.

rangement, it is contemplated that this practice be followed for low-valued calls and that for high-valued calls the same potential be connected to the speech path, but for a longer period in order to initiate the determination and transmission of the calling subscribers number. The switching operations in the latter case may be initiated in a simple manner by time zone metering equipment in the path reached over the repeater UE which, on the reply of the called subscriber, connects a potential corresponding to the metering potential to the lower conductor b of the junction line a/b. This time zone equipment has been omitted from the drawings since it forms no part of the present invention.

By means of this potential connection the following circuit is completed: earth in repeater UE, contact 68c2 winding of relay ZE, choke Dr3, lower talking conductor b and to the battery potential connected to the time zone arrangements. 'Ihe relay ZE in the repeater UE operates and completes the following circuit: earth, contact 65c2, winding I of relay U, contact 642e, 55s, 56k, resistance Wil I, battery, earth. In this circuit relay U operates, closes contact 61u and thus completes the following circuit: earth, winding II of relay U, contacts 622e, Glu, 54s, winding of relay K, battery, earth. In this circuit moreover, apart from the winding II of relay U, the relay K of the impulse sender SS energizes, opening its contact 56k and thus the circuit indicated above for winding I of relay U is broken. The completion of the energizing circuit of relay U (over winding I) of other repeaters is thus prevented. Further, the relay U closes contact 13u and thus completes the following circuit: earth, contacts II'cI, 13u, winding of relay C2, battery, earth. The relay C2 which at contact 'I0c2 extends metering current to the subscribers meter has a delayed armature release and thus operates only after a certain period. Thus the following result is obtained: In Fig. 2 at the top right hand side a repeater UEI associated with another connecting path is indicated. The contacts 58u and 59u of this repeater correspond to the contacts 60u and B I'LL of the repeater UE. When the relay U in a neighbouring repeater UEI operates owing to metering potential on its associated junction line and at this instant before operation of relay K the relay U of repeater U is energised, then, at contact 60u, the completion of a holding circuit for relay U (winding II) of neighbouring repeater is prevented. The relay U in the neighbouring repeater therefore operates for a short period only. In order that relay U in any repeater when energised momentarily in this manner shall not give rise to faulty operation of the meter by operation of relay C2 in that repeater this latter relay is arranged to have a slow armature operation so that it will operate only after a prolonged energisation of relay U.

When the relay C2 is operated on contact 13u being operated for the required length of time it holds for the duration of the connection in the following circuit: earth, contact 'I'IcI, 1202, Winding of relay C2, battery, earth. Relay U remains energised together with relay K until after the determination and transmission of the calling subscribers number in the following circuit: earth, winding II of relay U, contacts 6302, 6Iu, 54s, winding of relay K, battery, earth. Relay K closes its contact 95k and thus connects earth potential to the control relay and the contact eld. 'I'he relay C2 disconnects winding I of relay U at a further point, namely, contact c2, Further, it opens contact 68c2 and closes contact 6102. Thus earth potential is disconnected from the lower talking conductor. This can be used as a signal bringing switch means in the time zone arrangement into effect and terminating the potential connection to the lower talking conductor. Relays C2 and U energise and the following circuit is completed for the metering relay ZR in the first group selector: earth, battery, resistance WiI2, contacts 69u, 'IIlc2, choke Dr2, lower talking conductor, windings of the second and rst group selectors, choke DTI of the rst group selector, winding of metering relay ZR, earth.

Arrangements are known which make possible the transmission of an impulse over the talking conductors during the conversation without undue disturbances. In the drawings such arrangements are indicated by means of chokes, condensers and equalising networks between the conductors and which are connected to earth.

Metering relay ZR in the first group selector operates and closes the contact 221' thus bringing about a current increase on the blocking conductor c so that the meter of the calling subscriber operates. Since the contacts 69u and 'Iu2 in the repeater remain closed, for the time being the metering relay ZR. in the first group selector and hence the subscribers meter remain energised for some time.

The subscribers meters are so constructed that each metering magnet, in addition to operating the armature which steps the meter wheel, operates an additional contact. The metering contacts are arranged in groups and form a coordinate system of 10 rows of 10 contacts. In the embodiment meter contacts form a contact field: IH, 2H, 3H. Each contact of a subscribers meter is arranged in the iield according to the call number corresponding to the 100 digit. Within the field the contact for the meter of any particular subscriber is situated at the point which corresponds to the number determined by the last two digits of the call number. If the last three digits of a call number are for example, the digits 123, the contact of that par* ticular subscribers meter is arranged in the contact field IH for the first 100 and at this eld at the point which is formed by the abscissa 2 and the ordinate 3, It is therefore in the eld IH at the 3rd contact in the second row.

If the last three digits of a call number are 290, the contact of the subscribers meter is in contact field 2H, second 100s, at the point formed by the abscissa 9 and the ordinate l0. It is therefore the last contact 90 of the 9th row in contact field 2H.

In common for all contact fields IH, 2H, two groups of relays are provided which will be named as 10s control relays ZI--ZID and units control relays EI-EIO. The 10s control relays are situated on the abscissae running through all contact fields. Thus the control relay ZI marking the tens digit 1 is on the abscissa 1, and the control relay Z2 marking the tens digit 2 is on the abscissa 2. The units control relays EI--EI'D lie on the ordinate multipled together for al1 contact fields so that the control relay El marking the units digit 1 lies on the ordinate 1, the control relay E2 marking the unit digit lies on the ordinate 2".

Each contact eld is marked by special switch means. For this purpose in each of the rst two ordinates of contact field II-I a winding of GI is provided, in each of the ordinates 3 and 4 a winding of the relay G2, in each of the ordinates 5 and 6 a Winding of relay G3, in each of the ordinates 7 and 8 a winding of relay G4 and in each of the ordinates 9 and 10 of the relay G5. The contacts (259|, 2Ig2, 28g/3, 2994, 3g5) of relays GI-G5 connect the relay HI which marks the hundreds digit 1. Resistance Wi in parallel with relay I-II delays the operation of the relays armature for a reason which will be explained later.

'I'he same is the case in the other contact fields. In the ordinates of the Contact field 2H the relays Gli-GI I) are connected, in the field 3H the relays GI I-GI5. The contacts (3MB-Ill) connect the relay H2 marking the hundreds digit 2 and the contacts (32gl I-I5) connect the relay H3 marking the hundreds digit 3".

For connecting each of the relays H marking the hundreds digits, 5 relays G are provided for each contact field. Other solutions are possible which mark the contact field in which a particular metering contact lies with a smaller number of switch means.

It is assumed that a subscriber with a number 1125 has set up a connection. The contact of the meter of this subscriber is therefore connected in the contact field IH and at the point which has abscissa 2 and ordinate 5. This is therefore the fifth contact of the second row in the contact eld HI. When, after the reply of the called party, potential is connected to the lower conductor of the subsequent arranged time zone equipment, the meter Za of this subscriber :1.

is energised, and the metering contact 25 in the contact field IHis closed. 'Ihe following circuit is then completed: earth, contact 95k, windings I and II of tens control relay Z2, metering contact 25 in the contact field IH, winding I of relay G3, windings I and Il of relay E5, resistance W13, battery earth. The resistance ratios of the control relays are so selected that in the first place the units relay E operates and then the tens relay Z and final relay G. In the above-mentioned circuit the relay E5 first operates and by closing its contact 2965 shortcircuits its high resistance Winding. By means of the current increase thus produced the relay Z2 is operated, and closesits contact 122, shortcircuiting its high resistance Winding I. The further current increase operates relay G3 over its winding I.

The relay E5 closes its contact 'Ie5 in the units contact group EK and thus marks the units digit 5 of the call number in that the common contact 5NK of the impulse contact SS is connected over the marking line 5. The relay Z2 closes contact 8522 in the tens contact group ZK and thus marks the tens digit 2 of the call numbery in that the cam contact ZNK of the impulse sender is connected over the marking line 2. The relay G3 closes its contact 2893 so that the following circuit is completed: earth, battery, winding of relay HI, contact 28g/3, resistance Wi4, earth. A resistance Wi is connected in parallel with relay HI and causes relay HI to operate as a slow relay. Relay I-II closes contacts 8'IhI in the hundreds contact group HK and thus marks the hundreds digit 1 of the call group, actually the first thousands group, then 7 l if) by means of the relays HI--HID the thousands digit 1 of the call number is marked. All contacts of the thousands contact group TK therefore are connected to marking line 1 and over this with cam contact INK of the impulse sender. In the case assumed the connection of this contact is performed by contact Bhl.

All hundreds relays HI-HID have (at their contacts 40M, 4Ih2 to'42hlll) control over a relay group V/W which effects the connection and operation of the impulse sender SS. 'The impulse sender is connected by the closing of a metering contact with a considerable delayed operation since one only of the relays E can operate, then one of the relays Z, then one of the relays G and finally one of the relays H (slow). The delayed connection of the impulse sender is necessary so that its operation by normal (short) metering impulses which are transmitted from other connecting paths is prevented. Whenl a metering contact is closed for a short period, and one of the units and tens relaysV and perhaps one of the relays G can operate, but the normal metering impulse is much too short t0 operate a hundreds relay H over a G-relay. It will be seen that the normal (short) metering impulseA can never of itself start the impulse sender SS.

If simultaneously or almost simultaneously with the connection of potential for a longer period, the normal metering impulse is transmitted over other connecting paths then two meter contacts in the contact field will be closed at the same time. Long before either can operate an H relay, however, the normal metering impulse will have terminated causing the meter contactoperated thereby to restore. Finally over the metering contact which is closed for a long time the above-mentioned marking circuits are completed. When this has once been done and thev units and tens relays concerned have shortcircuited their high resistance windings then no other control relay can be operated notwithstanding the fact that other metering contacts may subsequently be operated by the normal metering impulses transmitted over other connecting paths. This is prevented by the locking circuit which extends according to the example as follows: earth, battery, resistance WiS, winding II of relay E5, contact 2Ile5, winding I of relay G3, metering contact 25 in contact field IH, winding II of relay Z2, contacts '122, 95k, earth.

The impulse sender SS consists of a' switch with forty-eight positions in which the positions I-I2, I3-24, 25-36, and 3'I--48, stepped over by the wiper ds are joined to contact segments. The contact segments II2 are connected to contacts Stihl, 9Ih2 to 92km of the thousands contact group TK. At the segments I3-24 the contacts BIhl, 88M to BShI of a hundreds contact group are connected.

The contact segment 25-36 is connected with contacts 842|, 8522 to 86am to the tens contact group ZK and the segment 31-48 with contacts "Mel, 'I5e2 to 83e!!! of the units contact group EK.

The impulse sender has ten cam contacts INK to IONK which are closed in certain positions of the impulse sender.

The contacts of the units, tens, and hundreds contact group are so connected with the cam contacts of the impulse sender that the contact marking a particular digit in each group is connected over the kcorresponding marking lines I-IU with its corresponding cam contact INK to IUNK. The contacts of the thousands group are however, as has already been mentioned, extended to the marking line I and over this to the cam contact NKI.

In the given example the following contacts in the individual contact groups are closed 18e5, 8522, 81h! and 90M. After the hundreds relay HI is switched in by means of Contact 28g3 the following circuit is completed: earth, contacts 40M, 43s, 44u), 45u, winding of relay W, resistance WiE, battery, earth. Relay W operates in this circuit and by opening contact Mw releases the winding of relay V from its short circuit so that this also can operate. The relay V closes its contact 16v and by shirt-circuiting relay W causes it to restore. The following circuit is now completed for relay X: earth, battery, resistance Wz`8, winding of relay X, contact 501.0, 4911, earth. Relay X closes contact 48a: and thus connects the magnet DS of the impulse sender so that its wiper ds is stepped on from the zero position to the rst contact. The magnet DS has a contact 52ds which is now closed and relay Y is connected: earth, contact 5201s, winding of relay Y, not short-circuited by contact 53x, resistance Wz'S, battery, earth. The relay Y closes its contact Sly and short-circuits winding of relay X. Contact 48m opens and disconnects the magnet DS. The relay Y is restored since contact 52de opens and contact 53m short-circuits the winding. The short circuit for relay X is opened at contact Iy so that this relay operates again. The interaction between relays X and Y and magnet DS continues until the wiper ds of the impulse sender has completed a rotation. The cam contacts INK to IONK are now closed in a particular manner in dependence on the position of the impulse sender and for a certain period. It is convenient to operate the cam contacts mechanically by means of cams on the shaft. The cam Contact INK for example, is closed in positions 2-I2, III- 24, 26-36 and 38--48 of the impulse sender. The cam contact 2NK is closed a step later, i. e. in positions 3--I2, I5-24, 21-36, and 39--48 of the impulse sender, and the cam contact 3NK in a further position i. e. in positions 4-I2, I6-24, 28--36 and 40-48. In Fig. 2 a table is given which shows the positions in which the different cam contacts are closed.

When the impulse sender has executed its rst step the wiper ds is operated from zero position to the first contact segment I-I2 and the shaft contact 9611s!) is opened together with the short-circuit for the winding of the impulse relay J. As mentioned above the relay Y energises after each connection of magnet DS at contact 52ds. When wiper ds reaches the first contact the following circuit is completed: earth, battery. resistance Di?. contact 411/. winding of relay J, resistance Wz'B. earth. In this circuit relay J operates which by closing its contact 519 transmits the rst impulse for marking the rst digit of the call number of the calling subscriber on the lower talking conductor on the following nath: earth. battery, resistance WzIU, contacts F14. 66u. 61c2, winding of relay ZE, choke DTS, lower talking conductor b. This impulse travels over the junction line to the station where a registering arrangement is provided (printing or punching device) and typewheels are set corresponding to the impulses transmitted. If the impulse sender has stepped. its wiper ds into the position 2 the cam contact INK is closed. When relay Y is connected again by contact 52ds the impulse relay J receives no impulse since the following shortcircuit is completed for its winding: earth, battery, resistance Wi1, contact 411/, wiper ds of contact segment I-I2, contact Bhl, marking line I, cam contact INK, resistance Wi, earth. In the given example therefore a single impulse only is transmitted for marking the thousands digit of the call number. In the registering arrangement the type wheel for the thousands digit is therefore positioned on contact 1. The short-circuit of relay J completed by the closing of contact 411/ continues as long as the Wiper ds is on contact segment I-I2 since the cam Contact INK is closed in positions 2--I2 of the impulse sender.

The impulses for marking the hundreds digit of the call number are transmitted while the wiper als is on the second segment I3-24. In the hundreds contact group HK, contacts B1h| which is connected with the cam contact INK is closed. In the position I3 of the impulse sender the cam contact INK is opened. It closes in positions I 4-24. After contact I3 has been reached and relay Y is connected at contact 52ds, relay J energises since it is not short circuited and, by closing Contact 51j, transmits an impulse over the lower talking conductor to the registering arrangement. If the Wiper ds is switched from contact I3 to contact I4 impulse relay J can no longer be energised after relay Y operates and contact 41g closes since the follow ing short-circuit exists: earth, battery resistance Wi1, contact My, wiper ds of contact segment I3 to 24, contact 81hI, marking line I, cam contact INK, resistance Wi, earth. Thus for marking the hundreds digit of the call number a single impulse only is transmitted. In theY registering arrangement the type-wheel for the hundreds digit is thus set on digit l". The relay J cannot be energised on further stepping on of the impulse sender since contact INK remains closed until wiper ds has left segment I3-24. The transmission of the marking signal for the tens digit of the calling subscribers number follows. In the tens contact group ZK contact 8522 which is connected over marking line 2 with the cam Contact 2NK has been operated. This contact is opened in positions 25 and 26 of the impulse sender and closed in positions 21 to 36. When the wiper ds has reached contact 25 and relay Y is connected, relay J is energised in the previously mentioned circuit so that an impulse is transmitted to the registering arrangement by the closing of contact 517. When the wiper ds reaches contact 26 and relay Y is operated, relay J is again energised and a second impulse is transmitted to the registering arrangement. When the wiper ds is stepped further and reaches contact 21, after relay Y is connected and contact 41g closed, the relay J can no longer be energised since the following short-circuit is completed for its winding: earth, battery, resistance Wi1, contact 41g, wiper dsof the contact segment 25 to 36, contact 8522, marking line 2, cam contact 2NK, resistance Wi6, earth. When the impulse sender is stepped on over segments 25-36 the relay J is no longer operated. For marking the tens digit of the calling subscribers number two impulses are thus transmitted to the registering arrangement and the type wheel for the tens digit is set on digit 2. A

The units digit of the call number is now marked. In the units contact group EK the contact 18e5 has been operated and is connected with marking line 5 and cam contact SNK. The cam contact SNK as can be seen from the table in Fig. 2 is open in positions :il-4| of the imof potential to the lower talking conductor, the

pulse sender and closed in positions 42--43.

When the wiper ds reaches Contact 31, the impulse relay J receives an impulse after relay Y is connected which is transmitted to contact 517'.

for registering. When the wiper reaches positions 38, 39, d and lll the relay J is energised each time and each time an impulse is transmitted to the registering arrangement. After ve impulses have been transmitted to the registering arrangement wiper ds reaches position 42 and immediately cam contact 5NK closes. Impulse relay J is not energised while the impulse sender is stepped further since the following short-circuit exists for its winding: earth, battery, resistance Wi'l, contact lily, wiperds of the segment 31-48, contact 18e5, marking line 5, cam contact SNK, resistance Wifi, earth. By means of the five impulses transmitted the typewheel for the units digit in the registering arrangement is set on position 5.

From this last contact wiper ds reaches the initial position in which contact iidsil is closed and the direct short-circuit for the Winding of the relay J is again in force. After relay Y is connected and releases and relay X by shortcircuiting its winding at contact Ely, the following-circuit is completed: earth, battery, resistance Wil, contact illy, wiper ds in the zero position, contact 93x, winding II and I of relay S, earth. Relay S operates in this circuit, opens contact 43s and thus the circuit for relay V. Relay V opens contact 49D and prevents further operation of the impulse sender SS. After. relay Y releases and contact lily opens the circuit for relay S is broken. Its release is somewhat delayed in View oi the short-circuit of its winding II at contact Ms. When relay S is energised contact Slis is opened and the circuit for relay U (winding II) of the repeater and relay K of the impulse sender is broken. Contact 69u opens and disconnects metering potential from the lower talking conductor b, restoring the relay ZR in the first group selector. Contact 2er opens and the potential necessary for energising the meter Za of the subscriber is again disconnected so that it restores.

Relay K releases and opens contact 95k in the impulse sender and the contact for the control relays, so that these restore. When contact 60u closes other repeaters can be connected with the common impulse sender SS for the purpose of determining and registering a calling subscribers number.

As is clear from the description as long as battery potential is connected over contact '1002 and 69u in the repeater to the lower conductor bv and therefore as long as relay ZR in the rst group selector and the subscribers meter Za. are both energised the determination and transmission of the number of the calling subscriber is continued. Normally the current increase is produced on the blocking conductor by metering relay ZR in the group selector for the purpose of operating the meter. When this stronger current is continued for some time, as in the present case, the danger arises that the cut-oi relay of another preselector testing on the seized group selector will operate, so that in view of the long application of a stronger current to the c-conductor double connections can occur.

To avoid such mistakes entirely the following arrangement is used: When the relay in the first group selector operates owing to the connection contact 22T is closed. The low resistance Wiz is connected over this contact and contact 3zel and, in this manner, the current increase necessary for operating the meter is produced on the blocking conductor. Resistance Wz'2is connected in parallel with a relay ZEI whose resistance is higher than that of resistance Wz'Z, and is so arranged that it has a delayed operation, and after opening contact Seel and disconnecting the low resistance WzZ, on the one hand maintains the meter Za operated for the Whole time relay ZR is energised, and on the other hand another testing preselector is no longer able to seize the group selector.

A :further embodiment is shown which prevents a double seizing of the group selector during the potential connection actually by setting up the blocking conductor in such a mannerasy that shown in the sketch (under the talking conductor b in the group selector IGW, Fig. 1) enclosed in a dotted outline.

When the relay ZR in the group selector is energised by the potential connection, contacts 4er and 5.21 are closed. The resistance Wil3 is connected by contact 421' and an electrolytic condenser EC by contact 5er. Wil3 is so arranged that testing on the seized group selector by another preselector is .y not possible. EC is connected a high charging impulse occurs, the meter is operated and is maintained in -its operated position over resistance Wil?. as the relay ZR is energised.

The determination and .transmission of the calling subscribers number need not be undertaken for each connection. It can be arrangedA `having an individual meter at the exchange,

means for extending a call from any of said stations, means effective after said call has been extended to operate the calling stations individual meter, and means common to said meters thereafter controlled by said Operated meter to register the number of said calling station.

2. In a telephone system, an exchange, subscribers lines terminating at said exchange, a set of contacts for each of said lines at the exchange, means in the exchange operated to extend a connection from any of said lines, means eiective after said connection is extended to operate the one of the sets of said contacts corresponding to the calling line, said one set of contacts remaining operated for a different length of time after different connections, and means controlled by said contacts if they are operated for a certain length of time after Athe extension of a connection to register the number of the calling line, said last means ineffective to register the number of the calling line if said The resistance At the moment when the condenser contacts are operated for a diierent length of time after the extension of the connection.

3. In a telephone system, an exchange serving a plurality of subscribers stations, a plurality of devices at the exchange each individual to one of said stations, a register common to said devices and controlled by each device, when that device is operated for a certain length of time, to register a different predetermined number, means for initiating a call from any one of said stations, means operated a variable interval of time after the initiation of certain calls to operate the device individual to the calling station for said certain length of time, thereby to operate said register, said last means operated at variable intervals of time after the initiation of other calls to operate the device individual to the calling station for a diierent length of time, said device ineffective to operate said register when operated for said diiferent length of time.

4. ,In a telephone system, a plurality of groups of subscribers stations, each station having an individual meter at the exchange, means for extending a call from any of said stations, means effective after said call has been extended to operate the calling stations individual meter, a device for each group of stations, and means controlled by the calling stations meter upon said operation thereof to actuate the device corresponding to the group to which the calling station belongs.

5. In a telephone system, an exchange, a plurality of groups of subscribers lines terminating at the exchange, each line having an individual set of contacts at the exchange, means in the exchange operated to extend a connection from any one of said lines, means effective after said connection is extended to operate that lines individual contact set, said set of contacts remaining operated for a different length of time after different connections, a device for each group of lines, and means controlled by said contact set if it is operated for a certain length of time to operate the device corresponding to the group to which said one line belongs, said last means ineifective to operate said device if said contact set is operated for a diierent length of time.

6. In a telephone system, an exchange, a plurality of groups of subscribers lines terminating at the exchange, each line having an individual set of contacts at the exchange, means in the exchange operated to extend a connection from any one of said lines, means effective after said connection is extended to operate that lines individual contact set, a group relay for each group of lines, a group of units relays common to all of said groups of lines, and means controlled by said operated contact set to operate the group relay corresponding to the group to which said one line belongs and also to operate one of said common relays to identify said one line within said group.

7. In a telephone system, a plurality of subscribers lines, a set of contacts for each line at the exchange, a register including a set of tens relays and a set of units relays, and means for operating any one of said contact sets independently of the other contact sets to complete a series circuit through one of saidtens relays and one of said units relays, thereby to register the tens digit and the units digit of the number of the line corresponding to the operated contact.

8. In a telephone or like system, means for registering multi-digit numbers, said means including a rst register for one of the digits of said number and a second register for another of the digits of said number, each register containing different relays corresponding to dierent values of the digit to be registered by that register, and

`means operable 'to complete a series circuit ing different relays corresponding to different values of the digit to be registered by that register, a resistance and a source of current common to said relays, means operated at a time when the registers are idle to complete a series circuit including any one of said relays of the rst register, any one of said relays of the second register, said resistance and said source, thereby to operate said two relays to register the two digits of a number, means thereafter operated ,s at some time during the existence of said series circuit to complete a second series circuit including any other of said relays of the rst register, any other of said relays of the second register, said resistance and said source, the voltage drop across said resistance in said rst circuit characterizing the registers as engaged and preventing the operation of said other two relays in said second circuit.

l0. A system as claimed in claim 9, wherein at least one of the relays operated in said rst circuit has a plurality of windings and is effective, upon operation, to close a shunt across certain of its windings, thereby to increase the voltage drop across said resistance.

l1. A register for use in telephone or like systems, including a plurality of register relays each corresponding to a different digit, a resistance common to said relays, a source of current, means operated at a time ,when the register is idle to complete a series circuit including any one of said relays, said resistance and said source, thereby to operate the relay to register a digit, means thereafter operated at some time during the existence of said series circuit to complete a second series circuit including any other of said relays, said resistance and said source, the voltage drop across said resistance in said rst circuit eective to characterize the register as engaged and to prevent the operation of said other relay.

12. A register as claimed in claim 1l, wherein each of said relays has a plurality of windings and is effective upon operation in said series circuit, to complete a shunt across certain of its windings, thereby to increase the voltage drop across said resistance.

13. A register for use in telephone or like systems, including a plurality of register relays each corresponding to a different digit, a resistance and a source of current common to said relays, a set of contacts for each relay, means for closing any oi said contact sets independently of the other contact sets, each contact set when closed connecting its associated relay to said source through said resistance, a plurality of said relays thereby being connected in parallel to one another if their associated contact Sets are operated concurrently, and each relay effective to operate only if connected to said source through said resistance at a time when no other of said relay is so connected.

14. In a telephone system, subscribers lines, line identifying equipment having a device individual to each of said lines, switching apparatus accessible to said lines, means for seizing said apparatus over any calling one of said lines and operating same to extend a connection, said switching apparatus thereafter controlled revertively over the extended connection to seize said identifying equipment, and means in said equipment common to all of said lines thereafter controlled by said device individual to the calling line to register the identity of said calling line.

l5. In a telephone system, subscribers lines, line identifying equipment having a device individual to each of said lines, switching apparatus accessible to said lines, means for seizing said apparatus over anyy calling one of said lines and operating same to extend a connection, said switching apparatus thereafter controlled revertively over the extended connection to seize said identifying equipment, and means common to all of said lines thereafter controlled by the device in said identifying equipment individual to the calling line to transmit impulses corresponding to the number of said calling line.

16. In a telephone system, subscribers stations having individual meters at the exchange, identifying equipment including a contact set on each meter, switching apparatus accessible to said stations, means for seizing said apparatus from any calling one of said stations and operating said apparatus to extend a connection, said apparatus thereafter controlled revertively over the extended connection to seize said identifying equipment, and means in said equipment common to all of said stations thereafter controlled by the contact set on the calling stations individual meter to register the identity of said calling line.

17. In a telephone system, subscribers stations having individual meters at the exchange, identifying equipment including a contact set on each meter, switching apparatus accessible to said stations, means for seizing said apparatus from any calling one of said stations and operating said apparatus to extend a connection, said apparatus thereafter controlled revertively overthe extended connection to seize said identifying equipment, means in the identifying equipment eifective upon said seizure of the equipment to operate the calling stations individual meter, and means common to all of said meters controlled by the contact set on the calling stations meter, responsive to said operation thereof, to register the identity of said calling line.

18. In a telephone system, subscribers lines, a device individual to each of said lines, a plurality of connecting paths, equipment common to said paths, means for extending a connection from any calling one of said subscribers lines over amr one of said connecting paths, means in said one connecting path thereafter controlled over the extended connection to cause said common equipment to be associated individually with said one connecting path, means in said common equipment then effective to operate the device individual to said calling line over said connection, and means in said equipment controlled by the operated device to identify the calling line.

19. In a telephone system as claimed in claim 18, means for maintaining said calling lines' individual device operated during said identication thereof, and means in said common equipment operated after completion of the identication to restore said device.

20. In a telephone system as claimed in claim 18, an impulse sender controlled by said identifying means to transmit impulses corresponding to the calling lines number, means effective to maintain the calling lines identification on said identifying means during the transmission of said impulses, and means in the sender for controlling said last means, upon completion of said impulse transmission, to remove said calling lines identification from said identifying means.

MAX LANGER. 

